Multimedia devices commonly use a plurality of dome switches that interact cooperatively with keys on the multimedia device. When a key is depressed by the user, the dome switch is activated so as to provide an electrical signal to the circuitry of the multimedia device.
FIG. 1 of the attached drawings shows an exemplary multimedia device 1 comprising a screen 2, a keypad 3, a navigator key 4 and additional keys 5. The navigator key 4 and the additional keys 5 allow the user to interact with a user interface displayed on the screen 2. The navigator key 4 and the additional keys 5 typically operate so as to interact with dome switches mounted on a printed wiring board.
FIGS. 2A and 2B show a cross section of a typical dome switch in a non-actuated and actuated state respectively. The typical dome switch comprises a dome sheet 7 having at least one conductive pad 8 on the concave surface of the typical dome switch. The typical dome switch further comprises a board 6 having a plurality of tracks thereon for passing electrical signals between the dome switch and other circuitry, said tracks connected to conductive contact pads 9. The typical dome switch is arranged such that upon actuation of said dome the at least one conductive pad 8 is brought into contact with conductive contact pads 9 so as to complete an electric circuit between said conductive contact pads 9.
The typical dome switch described above may be considered as a conductive dome switch whereby upon actuation of the switch the conductivity between conductive contact pads 9 is changed. However, such a dome switch may also be implemented wherein the capacitance between said conductive contact pads 9 is altered upon actuation of said dome switch
The navigator key 4 may be a 4-way switch. In this case the navigator key 4 interacts with four dome switches 12 mounted on dome sheet 11, shown in FIG. 3A. The position of the navigator key 4 is shown by outline 13 in this diagram. The navigator key 4 is arranged to pivot on a central point 14 equidistant from the four dome switches such that the user may tip the navigator key 4 so as to depress one of the dome switches 12 in order to interact with the multimedia device 1.
Dome switches or domes are designed with particular characteristics and qualities determined by the application for which they are required. Examples of these qualities are: force required for depression of the switch; amount of travel required by an activating member in order to depress the switch; the tactility of the switch; and the durability of the switch. The force, travel, and tactility of the switch all contribute to provide the user with feedback. The feedback may take the form of a clicking response at the key, and may even be accompanied by an audible click. It is important the user receives feedback upon depressing a key so as to increase the users satisfaction with the device. It is also important in the case that the information displayed on the screen 2 is not immediately updated after a key press in order to discourage the user from repeatedly pressing the key.
The navigator key 4 may alternatively have a 5-way operation. FIG. 3B shows the dome layout required for 5-way operation of the navigator key 4. Here, the navigator key interacts with 5 domes 12a, 12b, 12c, 12d and 15. Four of the domes 12a to d are arranged as discussed in relation to FIG. 2.
A central dome 15 is provided in the middle of the other four domes and is operated when the user applies pressure to a central portion of the navigator key 4. Activation of the central dome 15 may be interpreted by the multimedia device as a confirmatory response from the user such as “select” or “ok”.
The above described navigator keys have limited functionality, requiring a complicated and unintuitive user interface. This can cause the multimedia device to be difficult to use and make the accessing of particular functions of the device cumbersome for the user. This problem is becoming more pertinent to multimedia devices as these devices increase in complexity and have an increasing number of available functions.
It is an aim of embodiments of the present invention to solve or at least mitigate one or more of the problems described above.
It is another aim of the present invention to provide an improved user interface for a multimedia device that is advantageously more intuitive for the user.